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Choosing memory for i7-860: Clock rates or Latency?

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October 4, 2009 1:58:13 PM

I'm going to buy an i7-860 within two weeks and I have sorted out almost all parts of the system - with the exception of the RAM. I plan on buying the GA-P55-UD6 board, a neat 5870 and I'm kinda set on 8 gigs of RAM. Now my questions appear: Does this cpu react better on pure memory bandwith (i.e. buying 1600 or even faster) or on lower latencies (i.e. buying cl7 or better). I'm not fixated on a certain brand as my local vendor has a few brands that can be ordered. I thought about Kingston 1600 with CL9, but maybe 1600CL8 is far better? Or even 1333CL7?

I'm so confused and I didn't get a serious clou from reading reviews of the new Lynnfield-CPUs.
a b } Memory
October 4, 2009 5:18:19 PM

Most important is to make sure it's 1.5V - 1.65V RAM. Don't choose any with higher voltage.

Also, your motherboard/BIOS supports XMP features, which make it easier to get the most out of your RAM. You want to consider buying RAM with the XMP feature.

You might read this article by Tom's Hardware. It's long and filled with detailed testing of various RAM speeds with the i7. Read the conclusions on the last page - you'll see that in their testing, it's not worth the money to go even to 1600 RAM. But note they do recommend getting quick timings - which is lower latency.
http://www.tomshardware.com/reviews/memory-scaling-i7,2...

Basically, I would recommend a good name-brand DDR3 at 1333 with low CL/latency. For 8GBs, get 4 - 2GB modules. The 4GB modules are priced too high and give too limited a choice right now. And a low latency for 1333 is CL=7

So, I'd recommend one of these modules. There may be more out there.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

October 4, 2009 10:36:15 PM

I read a suggestion on AnandTech-Forums to go for exactly 1,5V because it's the only real standard-conform voltage - on the other points they suggestes the same as you.
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a c 109 } Memory
October 4, 2009 10:59:54 PM

As mongox said, there the i5/i7 cpu's do not scale hardly at all with faster ram and better timings, at least in real(non-synthetic) tests.
1.65 volt ram is really 1.5v ram that has the ability to overclock a bit. The higher speed 1.65v ram will be able to run at 1.5 volts which is what you want. Don't pay more unless you are a maximum overclocker. Also don't pay more for fancy heat sinks, fans, or "bling". Buy from a vendor with good US support. I have done well with Patriot and Corsair.

It might be good to get a matched 8gb kit instead of two 4gb kits.
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
a b } Memory
October 5, 2009 4:37:59 AM

make sure you get i7 compatible ram ( Voltages is the issue here)

personally I just get the cheapest ram i can find from a large manufacturer in the quantity and size i am looking for. the price difference you pay for performance ram verse the performance you gain is never worth it when money can be better spent else where. coincidentally it turns out to be muskin most the time

regardless i suggest you do some research as the board you have chosen uses 3 memory channels so for optimal performance memory should be sized in increments of 3 (say 3 2gig sticks giving you 6 gigs total) which will make a significant difference in performance vs 4 2gig sticks or two 4gig stick which would run in two channel leaving you with two unused mem channels
!